Their air-cooled design, which uses natural airflow as a cooling method, eliminates the risks of oil leaks and fire hazards, ensuring safer operation in various environments. Furthermore, their compact size in IP00 makes them suitable for space-constrained installations.
Maintenance is also simplified. The dry type transformers have fewer components that are prone to failure, minimizing interventions during their lifespan.
1. Structure of Dry Type Transformers
Dry type transformers function using solid insulation and natural or forced air cooling to maintain optimal operating temperatures. The primary components include:
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Core:
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HV and LV Windings:
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Insulation system:
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Cooling system:
Unlike oil-filled transformers, dry type units eliminate oil-related risks such as leaks, contamination, and fire hazards. Their compact size, particularly in IP00 ratings, allows installation in confined indoor spaces.
2. Benefits of Dry Type Transformers
Dry type transformers offer a unique combination of safety, sustainability, and operational reliability.
| Feature | Description | Benefit |
|---|---|---|
| Safety | No flammable oil | Reduces fire hazards |
| Sustainability | Eliminates risk of oil spills | Supports eco-friendly operations |
| Reliability | Low maintenance, robust design | Ensures uninterrupted power |
| Versatility | Suitable for indoor and protected outdoor use | Flexible installation options |
| Thermal Performance | High-temperature insulation materials | Handles load variations efficiently |
3. Types of Dry Type Transformers
Dry type transformers come in various designs depending on application requirements, thermal ratings, and insulation classes.
| Type | Cooling Method | Common Applications |
|---|---|---|
| Cast Resin | Air-cooled, epoxy insulation | Data centers, commercial buildings |
| Vacuum Pressure Impregnated (VPI) | Enhanced resin impregnation | Mining, industrial plants |
| Open Wound | Natural air circulation | Light industrial, education, office |
| Encapsulated | Fully sealed, epoxy-covered | Harsh environments, humidity control |
Cast Resin Transformers
Cast resin transformers use epoxy resin to cover windings completely. This provides excellent insulation, moisture resistance, and fire retardancy, making them suitable for commercial and industrial installations.
VPI Transformers
Vacuum Pressure Impregnation enhances insulation by saturating windings with resin under vacuum. This ensures high thermal stability, durability, and resistance to vibration, ideal for mining and heavy industry.
Open Wound Transformers
Open wound transformers rely on natural air cooling and are suitable for controlled environments. They offer cost-effectiveness and flexibility for smaller installations.
Encapsulated Transformers
Fully encapsulated transformers are designed for outdoor or harsh industrial environments. Their resin-coated windings protect against moisture, chemicals, and dust, ensuring reliable performance.
Dry type transformers for outdoor applications
With over 30 years of experience, Varelen Transformers has challenged the dry type transformers market by making them suitable for outdoor installation even in harsh environments. Our commitment to innovation and our R&D team developed and continuous improve advanced protective enclosures and cooling technologies to guarantee optimal performances in every condition, including high pollution, humidity, and corrosive elements.
Varelen products can be installed in special enclosures rated from IP21 to IP56, ensuring robust protection against dust and water ingress. We also offer solutions with IP67 ratings allowing the transformers to function safely underwater.
The enclosures can limit the natural airflow needed for cooling. To solve this, Varelen has created innovative cooling options as AFAF(Air Forced Air Forced) and AFWF (Air Forced Water Forced) heat exchangers to control temperature and improve efficiency, making them perfect for outdoor settings.
Protective Enclosures
| IP Rating | Protection Level | Typical Use |
|---|---|---|
| IP21 | Light protection against dust and vertical water drops | Semi-indoor or sheltered areas |
| IP44 | Dust and splashing water | Outdoor light industrial |
| IP56 | Dust-tight, water jet resistant | Heavy industrial outdoor |
| IP67 | Submersible, full water protection | Extreme environments, flooding-prone areas |
Cooling Technologies for Outdoor Installations
Outdoor installations often reduce natural airflow, so Varelen developed advanced cooling systems:
| Cooling System | Description | Advantage |
|---|---|---|
| AFAF (Air Forced Air Forced) | Dual air circulation | Maintains cooling efficiency |
| AFWF (Air Forced Water Forced) | Air and water hybrid cooling | Precise temperature control |
| Natural Convection | Standard airflow | Energy-efficient, low maintenance |
Comparative Overview: Dry Type vs. Oil-Filled Transformers
| Feature | Dry Type Transformer | Oil-Filled Transformer |
|---|---|---|
| Cooling Medium | Air | Oil |
| Fire Risk | Low | Higher due to flammable oil |
| Maintenance | Minimal | Moderate to high |
| Environmental Impact | Low | Risk of oil spills and contamination |
| Installation | Indoor & Outdoor (with protection) | Mostly outdoor or controlled environment |
| Size | Compact | Larger footprint |
Choose Varelen transformers for your power needs
By integrating these advanced technologies and features, Varelen Transformers offers tailored solutions that meet the specific customer needs, ensuring that the power supply remains reliable, safe, and efficient, regardless of the environment.
Discover more our wide range of dry-type solutions your power needs!
